| //===-- ResetMachineFunctionPass.cpp - Reset Machine Function ----*- C++ -*-==// |
| // |
| // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
| // See https://llvm.org/LICENSE.txt for license information. |
| // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
| // |
| //===----------------------------------------------------------------------===// |
| /// \file |
| /// This file implements a pass that will conditionally reset a machine |
| /// function as if it was just created. This is used to provide a fallback |
| /// mechanism when GlobalISel fails, thus the condition for the reset to |
| /// happen is that the MachineFunction has the FailedISel property. |
| //===----------------------------------------------------------------------===// |
| |
| #include "llvm/ADT/ScopeExit.h" |
| #include "llvm/ADT/Statistic.h" |
| #include "llvm/CodeGen/MachineFunction.h" |
| #include "llvm/CodeGen/MachineFunctionPass.h" |
| #include "llvm/CodeGen/MachineRegisterInfo.h" |
| #include "llvm/CodeGen/Passes.h" |
| #include "llvm/CodeGen/StackProtector.h" |
| #include "llvm/IR/DiagnosticInfo.h" |
| #include "llvm/InitializePasses.h" |
| #include "llvm/Support/Debug.h" |
| using namespace llvm; |
| |
| #define DEBUG_TYPE "reset-machine-function" |
| |
| STATISTIC(NumFunctionsReset, "Number of functions reset"); |
| STATISTIC(NumFunctionsVisited, "Number of functions visited"); |
| |
| namespace { |
| class ResetMachineFunction : public MachineFunctionPass { |
| /// Tells whether or not this pass should emit a fallback |
| /// diagnostic when it resets a function. |
| bool EmitFallbackDiag; |
| /// Whether we should abort immediately instead of resetting the function. |
| bool AbortOnFailedISel; |
| |
| public: |
| static char ID; // Pass identification, replacement for typeid |
| ResetMachineFunction(bool EmitFallbackDiag = false, |
| bool AbortOnFailedISel = false) |
| : MachineFunctionPass(ID), EmitFallbackDiag(EmitFallbackDiag), |
| AbortOnFailedISel(AbortOnFailedISel) {} |
| |
| StringRef getPassName() const override { return "ResetMachineFunction"; } |
| |
| void getAnalysisUsage(AnalysisUsage &AU) const override { |
| AU.addPreserved<StackProtector>(); |
| MachineFunctionPass::getAnalysisUsage(AU); |
| } |
| |
| bool runOnMachineFunction(MachineFunction &MF) override { |
| ++NumFunctionsVisited; |
| // No matter what happened, whether we successfully selected the function |
| // or not, nothing is going to use the vreg types after us. Make sure they |
| // disappear. |
| auto ClearVRegTypesOnReturn = |
| make_scope_exit([&MF]() { MF.getRegInfo().clearVirtRegTypes(); }); |
| |
| if (MF.getProperties().hasProperty( |
| MachineFunctionProperties::Property::FailedISel)) { |
| if (AbortOnFailedISel) |
| report_fatal_error("Instruction selection failed"); |
| LLVM_DEBUG(dbgs() << "Resetting: " << MF.getName() << '\n'); |
| ++NumFunctionsReset; |
| MF.reset(); |
| if (EmitFallbackDiag) { |
| const Function &F = MF.getFunction(); |
| DiagnosticInfoISelFallback DiagFallback(F); |
| F.getContext().diagnose(DiagFallback); |
| } |
| return true; |
| } |
| return false; |
| } |
| |
| }; |
| } // end anonymous namespace |
| |
| char ResetMachineFunction::ID = 0; |
| INITIALIZE_PASS(ResetMachineFunction, DEBUG_TYPE, |
| "Reset machine function if ISel failed", false, false) |
| |
| MachineFunctionPass * |
| llvm::createResetMachineFunctionPass(bool EmitFallbackDiag = false, |
| bool AbortOnFailedISel = false) { |
| return new ResetMachineFunction(EmitFallbackDiag, AbortOnFailedISel); |
| } |